Thermoplastic elastomers based on difunctional, telechelic soft segments have exceptionally desirable properties. Examples of difunctional telechelic soft segments useful in such thermoplastic elastomers include polyisobutylene-based soft segments. There are many unique and desirable physical and mechanical properties that are offered exclusively by polyisobutylene and polyisobutylene-based materials, including thermal stability, biocompatibility and gas impermeability, among others. These properties can be tuned and further modified in copolymerization strategies with other materials, for example, to synthesize polyurethanes based on a polyisobutylene (PIB) soft segment. A process of making polyisobutylene-based soft segments by carbocationic polymerization begins with a difunctional initiator molecule and produces a polyisobutylene diol.
Some of the materials used in the process of making polyisobutylene diol are costly, hazardous, and difficult to handle. Safer and less costly materials are needed.